Gripper device for conveying workpieces in hot die forging presses

ABSTRACT

This is a gripper device for conveying workpieces in hot die forging presses. The device includes tongs like gripping means working in conjunction with locking means which respond to a spring system for opening and closing the tongs like grippers.

United States Pa tent GRIPPER DEVICE FOR CONVEYING WORKPIECES IN HOT DIE FORGING PRESSES 7 Claims, 5 Drawing Figs.

Int. Cl B66c 1/42 Field of Search 214/115,

[56] References Cited UNITED STATES PATENTS 1,620,778 3/1927 Odom 214/ 1(B2 )X 1,721,283 7/1929 Ruth.... 294/116UX 1,730,705 10/1929 Wild.... 294/110X 3,430,779 3/1969 McElroy.. 214/](B2) 3,432,042 3/1969 Bautz 214/1(B2) FOREIGN PATENTS 216,846 12/ 1 909 Germany 294/ 1 06 Primary Examiner-Gerald M. Forlenza Assistant Examiner-George F Abraham 7 Attorney-Lowry, Rinehart & Markva ABSTRACT: This is a gripper device for conveying workpieces in hot die forging presses. The device includes tongs like gripping means working in conjunction with locking means which respond to a spring system for opening and closing the tongs like grippers.

PATENTED JAN 1 9 l9?! SHEET 1 OF 2 gall/4% INVENTOR ROLF EERGEK ATTYS.

PATENIEUJANISIBH 3.656315 sum 2 or 2 IN VE N TOR Ron- HERA ER BY ga m9 W ,qrrrs,

I BACKGROUND OF THE INVENTION Conveying grippers having a prismatic aperture for gripping symmetrical tubular parts such as billet pieces and the like or die forgings of rotationally symmetrical type forged from billet pieces are already well known. These prior art grippers are generally mounted to be resiliently" mobile in the gripper direction so that all workpieces which are'situated in the conveying system are gripped with the same application pressures. The workpiece is engaged by means of the prismatic aperture of the grippers above and below the workpiece at the sides thereof. The workpiece may also be engaged above and below the forging fin which is formed in the forging operation. The workpiece is forcibly held and conveyed by the prismatic elements of the grippers.

In die forging, the workpiece is released from the conveying system at the instant of forging. and reengaged after the pressing operation has been completed. It may happen that the workpieces do not detach unifonnly from the die. The forging flash is no longer in a plane parallel to the die division but is at an oblique angle ize. at one side the forging flash contacts the flash tin and at the opposite side is at a correspondingly considerable spacing from the tin. As a result the conveying grippers cannot engage the forging correctly. The prismatic element cannot press against the workpiece in order toengage it symmetrically. Instead'the elements abut against the forging flash thereby causing a disturbance in the 7 processing sequence.

Q SUMMARY OF THE INVENTION An object of this invention is to provide a conveying gripper I for hot die forging presses with a mechanical workpiece conveyance wherein a workpiece may be reliably engaged independently of its position in the die.

Another object of this invention is to provide a conveying gripper for hot die forging presses wherein a forging workpiece which is not rotationally symmetrical may be suitably handled by the said gripper device. I u

The device of this invention includes aworkpiece gripper which includes tongs elements which are controlled by actuating and locking devices. The gripper device includes two tongs elements which are connected at a common point and there fore have a common articulation. Tongs elements are contained in a body wherein each said elementis mounted on a longitudinally displaceable pivot pin which is movable with respect to the said tongs body. Each tongs element further includes a supporting and locking extension having a locking element associated therewith. The ends of the extensions en'- gage over the locking element in a manner to carry out locking of the gripper tongs elements. The body containing the elements of the workpiece gripper moves both invhorizontally and vertically oriented planes. 7

The structure of the gripper device provides automatically opening and closing tongs jaws. As the body of the tongs jaws moves horizontally in the direction toward the workpiece, the

jaw ends produce a force locking connection against the said I workpiece. At the same time the closing tongs jaws grip the forging flash in a positive connection which holds the work piece completely securely and unequivocally in its position in the die. Even though forgings are-no longer situated precisely I horizontally in the die cavity when the dies are opened after a particular shaping step or on ejection of the workpiece from the dies, the tongs jaws will engage and align the forging workpiece with a positive gripping action. In other words, the tongs can securely engage and transport both symmetrical and asymmetrical forgings at any time. The gripper device is simple in construction and always operates in a reliable manner mechanically. I 1

Another feature of the invention provides for the lower tongs element to engage an inclined surface located on the forging die. In this way, the closing operation of the tongs is initiated upon engagement with the inclined surface.

" and 3 include jaw ends 10 and II at the front and end exten-.

A spring system is used for the opening operation. A pistoncylind er unit can be used wherein a piston rod acts on the tongs-element at a location between the pivot pin and the common connecting articulation point with a second tongs element.

BRIEF DESCRIPTION OF DRAWINGS The invention will be explained hereinafter with reference to the examples of embodimentsillustrated in the drawings in which: P

FIG. I shows a longitudinaksectional view of a gripper device according to the invention wherein thedevice is in an open position and shown in conjunction with a dieand a workpiece situated therein,

FIG. 2 Ba longitudinal sectional view showing the gripper device-having the grippers engaged with the workpiece at the flash transition region, and

FIG. 3 shows a longitudinal sectionalview of the gripper device wherein the tongs elements are locked by the tongs body,

ofFlG. 2, and

FIG.'5 is a diagrammatic sketch illustrating the movement of the conveying beams or bodies on which the conveying grippers are arranged.

I DESCRIPTION OF SPECIFIC EMBODIMENTS sions I2 and 13 respectively at the rear. The end extensions I2 and 13 are used as hearing and locking portions and cooperate with a locking element 14 which is fixedly mounted on the tongs body 8. The extension 13 includes a nose 130 which engages the lower portion of the locking element 14.

A spring system acts to effect the opening of the tongs elements 2 and 3. The spring system of this specific embodiment includes a piston 15, cylinder 16 and piston rod 17. The piston rod 17 abuts the tongs element 2 between the pivot pin 4 and the connecting articulation 9. The tongs body 8 is mounted on a conveying beam 18. The tongs body 8 may be adjusted in the horizontal and vertical directions with respect to the beam 18 by way of adjusting means 19 and 20. The conveying beams 18 are movably mounted on means not shown to efiect movements 21 and 22 relative to the tool center 23. These movements are diagrammatically shown in FIG. 5. A workpiece 25 is maintained in the die 24 during the overall forging operation. The die 24 includes an inclined surface 26 which cooperates with the jaw end 11 on the tongs element 3. The jaw ends 10 and 11 act on the workpiece 25 at the forging flash 27.

A pair of gripper devices as shown in FIG. I move from both sides of the workpiece 25 in a horizontal direction x. In this way, the tongs elements 2 and 3 are moved uniformly by way of the conveying beams 18 to a position for gripping the forg" ing flash 27. The workpiece'25 may be slightly raised in the die 24 by means of a lower ejector means which is not shown. During this horizontal movement in the direction x, the tongs elements 2 and 3 are held open by the spring system 15, I6 and 17. Compressed air acting on the piston 15 presses the piston rod 17 against the tongs element 2. The tongs element 3 is held open during this operation by means of the connecting articulation 9. As the gripper device 1 moves toward the workpiece 25, the jaw end ll slides on the inclined surface 26 of the die 24. As the jaw end 11 moves toward a closed position by rotating about the pivot pin 5, the upper tongs element 2 is actuated by the movement of the jaw end It through the connecting articulation 9. During this closing operation, the ex FIG. 4 shows a cross-sectional view taken on the line IV-IV tensions 12 and 13 bear on the locking element and the two jaw ends 10 and 11 are held at the pins 4 and 5 in the forward position. When the tongs elements 2 and 3 have engaged the forging flash 27, the front edges of the jaw ends and 11 bear on the workpiece 25 in the x direction.

Once the tongs elements 2 and 3 have engaged the forging flash 27, the extensions 12 and 13 are so far apart from one another that further advancement of the conveying beam in the x direction toward the die 24 causes the extensions 12 and 13 to slide over the locking element 14 thereby effecting the first part of the locking operation. As the extensions 12 and 13 slide over the locking element 14, the tongs elements 2 and 3 shift in the longitudinal x direction by displacement in slots 6 and 7 of the tongs body 8 thereby completing the locking operation. The forging flash 27 is positively held by the tongs jaws 10 and 11 with a vertically directed action once the tongs elements 2 and 3 are positively locked in this manner. The workpiece 25 may then be conveyed to another position in accordance with the lines 21 and 22.

After conveyance to another position by means of the conveying beam 18, the spring system 15, 16 and 17 is again actuated to release extensions 12 and 13. Pressure applied in the cylinder 16 pushes the piston 15 and thereby moves the locking element 14 out of contact with the extensions 12 and 13. Continued application of pressure in the cylinder 16 causes the piston rod 17 to push against the tongs element 2 in the longitudinal x direction. The tongs elements 2 and 3 shift in the longitudinal x direction by displacement in the slots 6 and 7 respectively of the tongs body 8. As the tongs elements 2 and 3 rotate about the pins 4 and 5 respectively, the jaws 10 and 11 are forced open. This completes the releasing operation of the gripper device 1. The conveying beams 18 are then returned to their initial position with the tongs elements 2 and 3 opened.

Other types of mechanisms within the ordinary skill of the art may clearly be substituted in place of the piston-cylinder unit 15, 16 and 17.

While the gripper device has been shown and described in detail, it is obvious that this invention is not to be considered as being limited to the exact form disclosed, and that changes in detail and construction may be made therein without departing from the spirit of this invention.

lclaim:

1. An assembly for conveying workpieces in a hot die forging press comprising:

a. gripper means including a tongs body and tongs elements pivotally mounted and longitudinally displaceable in the tongs body;

b. means for moving the gripper means in planes perpendicular to and planes parallel with the workpiece;

c. said tongs elements having a common articulation point and having a structural configuration to provide opening and closing action when one of the elements is moved;

(1. a locking structure disposed rearwardly of the tongs elements; 5

c. said tongs elements including extension.portions projecting rearwardly thereof to engage the locking structure which is located between the extension portions when the tongs elements are in a closed position; and

f. an inclined surface structure located on the hot forging die to contact one of the to'ngs elements and cause it to move to the closed position when the gripper means movestoward the forging di'e.

2. An assembly as defined incl-aim 1 wherein said gripper means includes actuating means to 'maintain the tongs elements in an open position when'the gripper means moves toward the forging die. i

3. An assembly as defined in claim 2 wherein'the tongs elements open in a vertical direction and the inclined surface structure contacts a lower tongs element; said lower tongs element including a nose member located on the extension portion; said nose member contacting the locking structure when the tongs elements are in an open osition.

4. An assembly as defined in c arm 2 wherein said moving position of the gripper means with respect to the conveying beam.

5. An assembly as defined in claim 2 wherein said actuating means comprises a spring system.

6. An assembly for conveying workpieces in a hot die forging press comprising:

a. gripper means including atongsbody, tongs elements pivotally mounted and longitudinally displaceable in the tongs body, and actuating means to maintain the tongs elements in an open position;

b. means for moving the gripper means in planes perpendicular to and planes parallel with the workpiece;

c. said tongs elements having a common articulation point and having a structural configuration to provide opening and closing action when one of the elements is moved;

d. a locking structure disposed rearwardly of the tongs elements;

. said tongs elements including extension portions projecting rearwardly thereof to engage the locking structure which is located between the extension portions when the tongs elements are in a closed position;

f. an inclined surface structure located on the hot forging die to contact one of the tongs elements and cause it to move to the closed position when the gripper means moves toward the forging die; and

g. said actuating means comprises a piston-cylinder mechanism having a piston rod which engages the rearward side of the tongs elements between one of the pivot points of the tongs elements and the common articulation point.

7. An assembly as defined in claim 6 wherein the tongs elements include pivot pins which project into slots located in the tongs body; said slots extend in a direction substantially parallel to the forward movement of the gripper means. 

1. An assembly for conveying workpieces in a hot die forging press comprising: a. gripper means including a tongs body and tongs elements pivotally mounted and longitudinally displaceable in the tongs body; b. means for moving the gripper means in planes perpendicular to and planes parallel with the workpiece; c. said tongs elements having a common articulation point and having a structural configuration to provide opening and closing action when one of the elements is moved; d. a locking structure disposed rearwardly of the tongs elements; e. said tongs elements including extension portions projecting rearwardly thereof to engage the locking structure which is located between the extension portions when the tongs elements are in a closed position; and f. an inclined surface structure located on the hot forging die to contact one of the tongs elements and cause it to move to the closed position when the gripper means moves toward the forging die.
 2. An assembly as defined in claim 1 wherein said gripper means includes actuating means to maintain the tongs elements in an open position when the gripper means moves toward the forging die.
 3. An assembly as defined in claim 2 wherein the tongs elements open in a vertical direction and the inclined surface structure contacts a lower tongs element; said lower tongs element including a nose member located on the extension portion; said nose member contacting the locking structure when the tongs elements are in an open position.
 4. An assembly as defined in claim 2 wherein said moving means includes a conveying beam which carries the gripper means and includes means to adjust the vertical and horizontal position of the gripper means with respect to the conveying beam.
 5. An assembly as defined in claim 2 wherein said actuating means comprises a spring system.
 6. An assembly for conveying workpieces in a hot die forging press comprising: a. gripper means including a tongs body, tongs elements pivotally mounted and longitudinally displaceable in the tongs body, and actuating means to maintain the tongs elements in an open position; b. means for moving the gripper means in planes perpendicular to and planes parallel with the workpiece; c. said tongs elements having a common articulation point and having a structural configuration to provide opening and closing action when one of the elements is moved; d. a locking structure disposed rearwardly of the tongs elements; e. said tongs elements including extension portions projecting rearwardly thereof to engage the locking structure which is located between the extension portions when the tongs elements are in a closed position; f. an inclined surface structure located on the hot forging die to contact one of the tongs elements and cause it to move to the closed position when the gripper means moves toward the forging die; and g. said actuating means comprises a piston-cylinder mechanism having a piston rod which engages the rearward side of the tongs elements between one of the pivot points of the tongs elements and the common articulation point.
 7. An assembly as defined in claim 6 wherein the tongs elements include pivot pins which project into slots located in the tongs body; said slots extend in a direction substantially parallel to the forward movement of the gripper means. 